I see Sony sells these for $199, I wonder if this is a good buy and if anyone has purchased a refurb?

If I was interested in a refurbished 500, I would ask about the warranty. And if you are also interested, if you can also get the replacement warranty as well. I myself would not have an issue. It is supposed to be checked out by Sony to be in good working order.

When we are ready to get another car, one thing we might look into is factory refurbished.

The $100 buys you massive improvements in usability with the 505. The Sony PRS-505 can read .RTF and .PDF files NATIVELY from its internal memory (210MB) and its SD card (2GB max) and its MSPD card (8GB max) all at the same time. The PRS-505 charges from any USB port. The PRS-505 will work as a card reader on almost any system. I use mine, and have never installed the Sony s/w.